In doctors' offices, analytical laboratories and hospitals it is standard practice to obtain specimens of body fluids, particularly urine, from patients in order to analyze the specimens as an aid to diagnosis. Though the practice of analyzing specimens of urine and other body fluids is very old, handling of the specimens is still done in a crude manner, with the specimens given by the patient into containers of widely varying types, frequently without covers and frequently without any truly dependable means for assuring identification of the specimen as that of a particular patient. Thus, not infrequently, the specimen is collected in a glass bottle, carried about the office open, and simply placed on a piece of paper bearing the patient's name. In some doctors' offices and laboratories, an adhesive label is applied to the side of the bottle and the patient's name written on the label. In other cases, a wide mouth container is used, a cover is provided, and the label is applied to the cover. When open containers are used, the practice is unsanitary, because of spillage of portions of the specimen. When a cover is employed, the danger of spillage is reduced or eliminated, but a danger of confusion of specimens, so that the results of an analysis of one specimen are reported for a patient different from the one who gave that specimen, is generated, since the cover originally applied to one specimen container, and bearing the patient's name, is interchanged inadvertently with the cover from another patient's container. The advent of specimen containers molded from polymeric materials and equipped with removable covers has greatly improved the practice, but no adequate and inexpensive way has yet been provided for minimizing the danger that specimens and patients may be confused because of inadvertent application of the cover from one specimen container to the container of another specimen.